1. Field of the Invention
This invention relates to an anti-friction bearing, in which seal members are provided between inner and outer rings.
2. Description of the Prior Art
In an anti-friction bearing which comprises an inner ring, an outer ring and balls or like rolling elements provided between the inner and outer rings, seal members are provided between the inner and outer rings.
The seal members each comprise a metal core and a synthetic rubber member molded as a seal member on the metal core surface. When assembling such seals to produce anti-frictional bearings, they are stocked in a stacked form in a stocker of an automatic assembler.
The seals have to be supplied smoothly from the stocker to the automatic assembler. To prevent mutual sticking of the seals, the surface of the seal member molding of synthetic rubber is coated with an anti-sticking agent, for instance an oil mainly composed of silicon.
When the prior art anti-friction bearing is used for journaling in a rotary part of a precision machine, fine particles of the anti-sticking material are scattered in a gaseous form from the seal member surface to adversely affect other mechanisms in the precision machine.
For example, where the bearing is used for a rotary part of a hard disc drive motor, fine anti-sticking agent particles (of 1 .mu.m and above) may be attached to the surface of a magnetic disc, which is rotating at a high speed with slight interstices (of 1 .mu.m and below) provided between it and a magnetic head. The attached particles may collide with and cause damage to the magnetic head.